enger@GBURG.SCC.COM (11/28/88)
Mark: Your recent mail requesting a reduction in the volume of messages to the tcp/ip mailing list made me wonder what are the capabilities of SRI-NIC.ARPA. Is the mailer capable of attempting concurrent delivery to multiple recipients (not on the same host) of a single message? Is the mailer capable of attempting concurrent delivery of multiple messages? Have the Jacobson/Karels/Karn improvements to the TCP/IP protocols been incorporated in to SRI-NIC.ARPA? Thanks, Bob
BILLW@MATHOM.CISCO.COM (William Westfield) (11/29/88)
Here is how the the SRI-NIC.ARPA mailer works, in general. There are two queues for mail delivery. Each queue handles only one message at a time. The first queue handles first time delivery attempts. If a host is down, it is marked so, and further delivery attempts to that host (say, on additional messages) are skipped. The behavior of this queue affects the total number of messages per day that can be delivered. The second queue handles additional attempts for hosts that were down or other temporary failures... tcp-ip has 415 recipients at 296 different hosts. The last time I looked at this problem, most of the mailer's time was spent trying to open connections to hosts that were dead (as opposed to slow connections.) Perhaps things have changed since then. I am not worried even if the list CAN only handle 8 messages a day. If there are consitantly that many messages on the list, I would expect it to become digestified, or I will unsubscribe. In addition, because of the way the first mail queue works, a second message that arives durring the three hours it takes to process a first message will probably not take as long. SRI-NIC.ARPA doe NOT include the Karels/Jacobson modifications. On the other hand, being a tops20 system, it never behaved quite as poorly as 4.2 unix did in the first place... BillW -------